The Mud Calculator can also be used for a Kerdi shower floor. However, since a Kerdi floor has one layer instead of two, a few minor tweeks to the calculation process is required.

Illustration - Shower size is 4' x 6' (48" x 72").

Referring to the example below:

Depth of the mud bed at the drain is installer determined, in this case 1 ¼”.

Depth at the far wall using the ¼” slope per foot of run rule will be 2”.

We now have all the numbers necessary to complete the Input section of the Mud Calculator depicted below. Important note - you only need the Preslope input and output section of the Calculator. Totally ignore the Top layer deck mud thickness, leaving the default value of 1.5” as is.

Prepping brick for tile can be done a couple ways. If your brick is flat
without any major humps and bumps its safe to simply clean it up and
notch trowel over it with thinset.
If your brick isn't flat you might want to consider floating a new flat
and level float job right over the top to create a nice setting surface.

To prep for your mudjob you will need to clean the brick. A bucket of
water with a scrub bush to loosen the dirt and a sponge to wipe it up
will be needed. After cleaning the brick wipe it with a wet sponge a couple
more times to allow the brick to absorb water. You can also use a spray
bottle for this. Wetting the brick will help to stop the thinset and mud from
drying to fast and provide the best bond possible.

For this simple hearth i have used form boards made from clear redwood
screwed together at the corners and adjusted with shims to the desired
height. The height was determined prior to building the rest of the fireplace
with the intention of floating over the brick from the beginning.
While leveling the form boards close attention to making them square
should be made as well.

After the water has been absorbed by the brick and no more puddles
are visible you can begin work. For this application a modified thinset
was used to bond deck mud (play sand mixed 4-5 parts sand to 1 part
portland cement) Un modified thinset will work fine but i chose to work
with what was on the job.
Using a medium notch trowel, 3/16" v-notch or similar cover the entire
surface of the brick with thinset. Proceed after this by covering the
thinset with deckmud quickly to prevent the thinset from drying
out or "skinning over".

Spread the deckmud around and cover the thinset completely.
This will keep the thinset from skinning and keep the integrity of
the bond. The next step is to fill in the area being floated just above
the level of the form boards. Using a wood/resin or mag float compact
the deck mud with a medium to firm arm swing. The mud doesnt need
to beat to death but it should hold its place while shaping.

The last step in this process is to shape and finish the mud.
By using form boards the perimeter and plane of the mud
has already been created eliminating any need for additional
screeds. A metal or wood straight edge can be used to ride
the form boards while cutting the surface of the mud. With a
very light touch the float (resin/wood/mag) is used to smooth
out the final surface. Allow the mud to cure over night and
the boards are ready to be pulled off and the mud ready to tile!

I waited for the video to come from the mudcourse, "Alas" lol...Yet to see it. A friend caught wind from a post I made on facebook that I was going to be floating a tub surround and asked for pics. Well, since I have recently aquired an Ipod from my son that actually takes pretty nice video I decided to make one. I edited out quite a bit of stuff that was off screen and in an attempt to keep it to the file size allowed by youtube, This is what I came up with. "Floating a tub surround" : Don't be too hard on me, I'm no film maker....

Last but not least, Floating a tub surround part 4. This installment shows the finished tile job as well. I hope this helps someone. If I was trying to make money from this, I would have spent a lot more time and energy making it. Again, If it helps someone, I will be satisfied. Enjoy.